:root {
    --board-size: clamp(320px, 48vw, 540px);
}

.cg-wrap, .board-container {
    width: var(--board-size);
    height: var(--board-size);
    position: relative;
}

.gameplay {
    display: grid;
    gap: 2rem;
    align-items: start;
    justify-items: stretch;
    max-width: calc(var(--board-size) + 36rem);
    margin-block: 3.2rem 2rem;
    grid-template-areas:
        'board panel';
    grid-template-columns: var(--board-size) minmax(28rem, 34rem);
}

.board-container {
    grid-area: board;
    overflow: hidden;
    border: 1px solid rgba(23, 32, 28, 0.16);
    border-radius: 8px;
    box-shadow: 0 18px 42px rgba(23, 32, 28, 0.12);
}

.trailchess-panel {
    display: grid;
    grid-area: panel;
    grid-template-columns: minmax(0, 1fr);
    gap: 1.6rem;
    min-width: 0;
    padding: 1.8rem;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.78);
    box-shadow: 0 14px 34px rgba(23, 32, 28, 0.08);
}

.trailchess-status {
    display: grid;
    gap: 0.2rem;
    padding-bottom: 1.4rem;
    border-bottom: 1px solid var(--line);
}

.trailchess-status span,
.reserve-group > span {
    color: var(--muted);
    font-size: 1.2rem;
    font-weight: 760;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.trailchess-status strong {
    color: var(--ink);
    font-size: 2.3rem;
    line-height: 1.15;
}

.pocket-top {
    grid-area: pocket-top;
}

.pocket-bottom {
    grid-area: pocket-bottom;
}

.controls {
    display: grid;
    gap: 1.4rem;
    grid-area: auto;
    min-width: 0;
    width: 100%;
}

.controls fieldset {
    min-width: 0;
    min-inline-size: 0;
    margin: 0;
    padding: 0;
    border: 0;
}

.controls legend {
    margin-bottom: 0.7rem;
    color: var(--ink);
    font-size: 1.4rem;
    font-weight: 760;
}

.player-options {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    width: 100%;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: rgba(238, 243, 238, 0.75);
}

.player-options label {
    min-width: 0;
}

.player-options input {
    position: absolute;
    width: 1px;
    height: 1px;
    clip: rect(0 0 0 0);
    clip-path: inset(50%);
    overflow: hidden;
    white-space: nowrap;
}

.player-options span {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 4rem;
    padding: 0.7rem 0.8rem;
    color: #34433b;
    font-size: 1.35rem;
    font-weight: 720;
    line-height: 1.1;
    text-align: center;
    cursor: pointer;
    transition:
        background-color 180ms ease,
        color 180ms ease,
        box-shadow 180ms ease;
}

.player-options label + label span {
    border-left: 1px solid var(--line);
}

.player-options input:checked + span {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 8px 18px rgba(21, 88, 77, 0.18);
}

.player-options input:focus-visible + span {
    outline: 2px solid var(--copper);
    outline-offset: -2px;
}

.controls .reset {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 4.4rem;
    width: 100%;
    margin: 0.2rem 0 0;
    padding: 0.9rem 1.4rem;
    border: 1px solid var(--accent);
    border-radius: var(--radius);
    background: var(--accent);
    color: white;
    font: inherit;
    font-size: 1.45rem;
    font-weight: 760;
    line-height: 1.1;
    cursor: pointer;
    transition:
        transform 180ms var(--ease-out),
        border-color 180ms ease,
        background-color 180ms ease,
        box-shadow 180ms ease;
}

.controls .reset:hover {
    border-color: var(--accent-dark);
    background: var(--accent-dark);
    transform: translateY(-1px);
    box-shadow: 0 10px 24px rgba(21, 88, 77, 0.18);
}

.reserve-panel {
    display: grid;
    gap: 1.2rem;
    min-width: 0;
    width: 100%;
    padding-top: 0.2rem;
}

.reserve-group {
    display: grid;
    gap: 0.6rem;
    min-width: 0;
    width: 100%;
}

.description {
    grid-area: description;
}

.trailchess-page > p {
    color: var(--muted);
    font-size: 1.8rem;
}

.trailchess-quickstart {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.4rem;
    max-width: calc(var(--board-size) + 36rem);
    margin-block: 2.4rem 5.6rem;
}

.trailchess-quickstart article {
    padding: 1.8rem;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.72);
}

.trailchess-quickstart h2 {
    margin-bottom: 0.7rem;
    font-size: 1.9rem;
}

.trailchess-quickstart p {
    margin: 0;
    color: var(--muted);
    font-size: 1.45rem;
    line-height: 1.45;
}

.trailchess-page .pocket {
    display: flex;
    grid-area: auto;
    width: max-content;
    max-width: 100%;
    overflow: hidden;
    border: 1px solid rgba(72, 100, 122, 0.2);
    border-radius: 6px;
    background: rgba(238, 243, 238, 0.92);
    box-shadow: none;
}

.trailchess-page .pocket > piece:hover {
    background-color: rgba(35, 120, 105, 0.12);
}

.trailchess-page .pocket piece::after {
    background: var(--copper);
    box-shadow: none;
    text-shadow: none !important;
}

.trailchess-page .reserve-panel .pocket piece {
    width: 5.2rem;
    height: 5.2rem;
}

.cg-trails {
    overflow: hidden;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    opacity: 0.6;
}

.cg-trails .trail {
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    opacity: 1;
}

.cg-trails .trail-black {
    stroke: black;
}

.cg-trails .trail-white {
    stroke: white;
}

.cg-trails .trail-choose {
    stroke-dasharray: 0 4%;
}

@media (max-width: 860px) {
    .gameplay {
        grid-template-areas:
            'board'
            'panel';
        grid-template-columns: minmax(0, 1fr);
        max-width: var(--board-size);
        margin-inline: auto;
    }

    .board-container,
    .cg-wrap {
        justify-self: center;
    }

    .trailchess-panel {
        width: 100%;
    }

    .trailchess-quickstart {
        grid-template-columns: 1fr;
        max-width: var(--board-size);
        margin-inline: auto;
        margin-bottom: 4.8rem;
    }
}